udevd and slow login?

[Tom Horsley]

Just for grins I installed a script in rc.local to furiously
run ps f -e in a loop until it sees a gnome-terminal process
in the list and record the results in a log file.

I got about 40 MB of ps listings (which is a lot to look at :-),
but the most interesting bit I did see was this:

  454 ?        Ss     0:00 /lib/systemd/systemd-kmsg-syslogd
  463 ?        Ss     0:00 /sbin/udevd
  467 ?        S      0:00  \_ /sbin/udevd
  468 ?        S      0:00  \_ /sbin/udevd
  469 ?        S      0:00  \_ /sbin/udevd
  470 ?        S      0:00  \_ /sbin/udevd
  471 ?        S      0:00  \_ /sbin/udevd
  474 ?        S      0:00  \_ /sbin/udevd
  475 ?        S      0:00  \_ /sbin/udevd
  476 ?        S      0:00  \_ /sbin/udevd
  477 ?        S      0:00  \_ /sbin/udevd
  478 ?        S      0:00  \_ /sbin/udevd
  479 ?        S      0:00  \_ /sbin/udevd
  480 ?        S      0:00  \_ /sbin/udevd
  481 ?        S      0:00  \_ /sbin/udevd
  482 ?        S      0:00  \_ /sbin/udevd
  483 ?        S      0:00  \_ /sbin/udevd
  484 ?        S      0:00  \_ /sbin/udevd
  485 ?        S      0:00  \_ /sbin/udevd
  507 ?        S      0:00  \_ /sbin/udevd
  508 ?        S      0:00  \_ /sbin/udevd
  509 ?        S      0:00  \_ /sbin/udevd
  510 ?        S      0:00  \_ /sbin/udevd
  511 ?        S      0:00  \_ /sbin/udevd
  512 ?        S      0:00  \_ /sbin/udevd
  514 ?        S      0:00  \_ /sbin/udevd
  515 ?        S      0:00  \_ /sbin/udevd
  516 ?        S      0:00  \_ /sbin/udevd
  517 ?        S      0:00  \_ /sbin/udevd
  518 ?        S      0:00  \_ /sbin/udevd
  519 ?        S      0:00  \_ /sbin/udevd
  520 ?        S      0:00  \_ /sbin/udevd
  522 ?        S      0:00  \_ /sbin/udevd
  526 ?        S      0:00  \_ /sbin/udevd
  527 ?        S      0:00  \_ /sbin/udevd
  528 ?        S      0:00  \_ /sbin/udevd
  529 ?        S      0:00  \_ /sbin/udevd
  540 ?        S      0:00  \_ /sbin/udevd
  541 ?        S      0:00  \_ /sbin/udevd
  542 ?        S      0:00  \_ /sbin/udevd
  543 ?        S      0:00  \_ /sbin/udevd
  544 ?        S      0:00  \_ /sbin/udevd
  545 ?        S      0:00  \_ /sbin/udevd
  546 ?        S      0:00  \_ /sbin/udevd
  547 ?        S      0:00  \_ /sbin/udevd
  548 ?        S      0:00  \_ /sbin/udevd
  549 ?        S      0:00  \_ /sbin/udevd
  550 ?        S      0:00  \_ /sbin/udevd
  551 ?        S      0:00  \_ /sbin/udevd
  552 ?        S      0:00  \_ /sbin/udevd
  553 ?        S      0:00  \_ /sbin/udevd
  554 ?        S      0:00  \_ /sbin/udevd
  473 ?        Ss     0:00 /lib/systemd/systemd-readahead-collect

Those udevd kids showed up for a long time during the ps loop.

What the heck is udevd doing with all those kids, and could
it be what is responsible for it taking 20 seconds to do
a login after the initial boot?